The present invention relates to a coating composition which forms a dyeable, cross-linked, hardened film on a substrate to which it is applied, the film exhibiting high abrasion resistance, surface smoothness, antistaticity and cloud prevention properties when cured by irradiation with active energy rays in air.
Synthetic resin moldings made of polymethyl methacrylate, polycarbonate or polyallyldiglycol carbonate materials have various commercial advantages in that they are not only lighter in the weight and substantially more shockproof than a glass product, but they are also cheaper in price and easier to fabricate and mold than glass products. Accordingly, these materials have several practical applications in replacements for their glass counterparts such as organic glass plates, light fixture covers and diffusion panels, optical lenses, eyeglass lenses, sunglass lenses, reflectors and mirrors, display panels, signboards, commercial advertising displays, name plates, dust cover cases as well as automobile parts.
However, conventional synthetic resin moldings are particularly deficient in surface abrasion resistance properties and are susceptible to damage on the surfaces by contact with other objects, shocks and scratches during the transportation and storage or use. These surface scratches are not only detractive from an appearance aspect but also affect the properties of the article, for instance, scratches in the molded synthetic article when used as an optical surface in an optical device. A polyfunctional (meth)acrylate monomer has been described as exhibiting high cross-linking hardening on polymerization when irradiated with active energy rays and is effective to improve the abrasion resistance of the surface of a synthetic resin molding. This has been disclosed, for example, in U.S. patent application Ser. No. 878,830 filed on Feb. 17, 1978, now U.S. Pat. No. 4,199,421. Although synthetic resin moldings made by such a procedure have an excellent abrasion resistance and surface smoothness, they are likely to be readily staticized so as to attract and deposit dust or the like and have been difficult to dye. In addition, the coated surfaces of the resin moldings are easily clouded in humid environments.